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@TMeier 6 күн бұрын
Thanks! Clear and to the point
@CornellEngineers 3 күн бұрын
Thank you for your comment. We appreciate your feedback!
@boytjie733 7 күн бұрын
Hi Matt .... is it recommend to lay a concrete apron around the circumference of the house to protect the waffle slab foundations .... Many thanks Anthony
@RajatReactsTV 9 күн бұрын
What are the possible solutions to repair these?
@cameronvan6875 22 күн бұрын
❤👍
@user-wd3il6ko2q 27 күн бұрын
When slab mesh got cut due to vertical service pipe, some engineers specify "provide a 600*600 off cut of mesh, lap and tie to the underside of slab mesh". Just wondering does this off cut mesh has to be installed to the underside of the slab mesh or it can be located on top of the slab mesh?
@domgdesign299 Ай бұрын
My house has had slab heave and cracking. Its a great video. You dont mention a concrete apron around the house. Can you stop slab heave without concrete around house? If you need an apron can it be paver? What width? If you can get by with out a concrete or paver apron what do i do to stop slab heave? In regard to the clay plug were pipes go under house if not done or not sure if done is concrete over the area sufficient?
@mw-le1ug Ай бұрын
Matt, this is the best drainage video ive seen. 50s house built on a slopping block. Big sandstone shelf just below the surface. Lots of water moving on there rock shelf hence getting under the house, Unfortuanly i have to capture the water right at the house as there's sandstone boulders in the way of capturing further up. I'll defiantly get the wall waterproofed as I don't think it ever was. Id love to spoon drain it and but its about 2 metres below the and only about a 1 foot wide trench. How effective would a large ag pipe with the right fall covered in gravel? The thought I burying all my hard work with gravel scares me! Thank you
@milamf1529 2 ай бұрын
So clear and informative - sure could use your services - if only you were in Sydney!
@jass7899 2 ай бұрын
Have you got a video how to properly tap around the plumbing pipes? To not allow moisture through
@PkPushpender-wr8ib 2 ай бұрын
Sir ishka upaye kya hai
@kk99990000 2 ай бұрын
We just moved into a 4 year old house(reactive soil in melbourne, on waffle pod slab). In march, dug a post hole next to the wall in backyard. It keeps filling up with water which is coming from underneath house/slab. It was initially filling up at the rate of 1 litre/3 minutes but never overflowed. We started emptying it with the pump and eventually it slowed down but never completely stopped. Had couple of days rain and now it is filling up faster than before but still doesn't fill up to ground level. Except the front, all sides of the house have weed cloth with garden rocks on it. Soil grading on one side looks pretty flat. We initially though it was a leak in water supply but after the recent rain, it seems it is rain water which is getting under the house somehow. What can we do to resolve? kzbin.infoSpAxSMKo_Js?feature=share
@neilkohler860 2 ай бұрын
Hi are waffle slabs good idea on a excavated site mostly on blue stone rock levelled
@malyboyle223 2 ай бұрын
Thank you so much. This is just what I need and I think it'll move a lot of water away quicker than other grated drains available....plus I can do it myself😊 cheers
@CornellEngineers 2 ай бұрын
Thanks for the feedback. These are all excellent reasons for using a spoon drain over a grated drain. Matt
@alexc5369 3 ай бұрын
Thanks Matt, I wish I found you a bit sooner, I've started to dig a trench around 2 sides of my house for an ag drain, but I'm not 100% confident it is the solution. The lawn extremely saturated for days after a rain.. when you walk on the lawn you can hear the squelching through the grass and water comes up between the toes... After the last rain I dug a couple of investigative holes about 300-400mm deep, they were filling up with water, I would empty a couple hours again would fill up, multiple times over a couple of days. I am in Brisbane, I would love to organise someone to come have a look and assess before I go any further to give me some insight. Where abouts are you based? Thank you! Alex
@tonyl5888 3 ай бұрын
If there’s foundation problem. Do we need a professional structural engineer to do a report before conducting underpinning or foundation repair? Does it require building approval?
@MichaelaBenson-oi2pz 3 ай бұрын
Thanks for confirming that the vapour barrier goes under the foam insulator.
@jonathantezbir1178 4 ай бұрын
Great video! Appreciate you sharing your knowledge! Just subscribed and liked.
@johnmills-dg8zr 4 ай бұрын
Thanks Matt, you answered my questions on isolating the moisture problem
@CornellEngineers 4 ай бұрын
Very glad I could help John. All the best. Matt
@Lex-wx3ib 4 ай бұрын
simple solution that every Italian did when he built his house in the 60s: lay concrete over the entire block. No grass, no weeds, no water damage.......no worries mate! 😂
@danchesney631 4 ай бұрын
Instead of a pile cap that might try to lift the pile with surface frost, how about a collar with radial fins, that is pressed into the surface?
@CornellEngineers 4 ай бұрын
Hi Dan Sounds like an option for lateral stability without being affected too much by frost heave (clay heave in Australia). However The collar and radial fins would have to be protected from corrosion and somehow transfer enough lateral load through the fins into the adjacent ground without pushing into the ground. Then the whole assembly needs to not ever be damaged by homeowners, mowers and future renovations. Solve those issues and you might have a plan!
@danchesney631 4 ай бұрын
How about not removing the soil that comes up around the screw pile, & following up with a vibratory compactor after each pile is installed?
@CornellEngineers 4 ай бұрын
Hi Dan Maybe. That would recompact the soil - but the screw pile steel shafts are quite narrow meaning that if they push sideways from bracing loads or buckling, the stresses into the surface level soils would be very high. Some good thoughts Dan. But I'm not a fan of compacted soil as the answer! Matt Cornell
@brakesreleased 7 ай бұрын
I’m in Alaska where we also have to contend with frost heave. Additionally, in virtually all owner hired contractors its an imperative to be knowledgeable about what your buying to ensure the job is being done correctly. Your educational video is exactly what I’ve been looking for and appreciate the fact that you’ve taken the time to share in detail your knowledge and experience. I feel better armed going forward preparing a foundation for my log cabin.
@romaindappe4139 7 ай бұрын
Ok but ive never seen a house where some cornices didnt crack or separated from wall/ceiling. Our house built in 2007 has damaged cornices in pretty much every room and I'm not keen on spending money on cornices as i find them ugly. Squareset makes a low ceiling look higher too. Is a cracked squareset more problematic than a cracked cornice?
@llanzafa 8 ай бұрын
Great work thanks mate
@ws9656 8 ай бұрын
Apakah retakan seperti itu wajar atau tidak
@alfalders3020 8 ай бұрын
Very smart 👍
@alfalders3020 8 ай бұрын
Excellent video. Thank you very much 👍
@nataliecrocker4963 10 ай бұрын
What if your house block is lower than the road and there is no storm water drain
@Matthew_Cornell_Photography 10 ай бұрын
Hi Natalie It depends on a few things. How old is your house? Where is your legal point of stormwater discharge? Rules vary with different areas. Only very rarely do councils ask you to make water flow uphill. Matt
@mantisbog 10 ай бұрын
Why can't you leave the jack under the house instead of messing around with all that messy concrete?
@CornellEngineers 10 ай бұрын
Good question. You can - but better still why not do both? Leave the jack there and backfill with concrete also. Jacks are a lot cheaper than they used to be - but still not as cheap as steel packers and some concrete.
@royjack7217 10 ай бұрын
As a migrant engineer i was struggling to understand australia code as i have only ACI code knowledge. you are a really true man that i have learned a lot from your youtube video .
@Preparationmadeasy 10 ай бұрын
Same type cracks observed in my House also. Isnit. Repairable?. Will it lead to sudden collapse? Much worrying
@AnuditDas 4 ай бұрын
Hello is there any problem now ?? Is it normal?
@tooshay7396 11 ай бұрын
it appears to be going in at an angle? Potential issues later?
@markharwood 11 ай бұрын
Thanks for the very informative video. When the engineer designs for screw piers I'm assuming they just specify the rotational torque that needs to be reached when insallting the screw pier? Is this enough to determine that the pier is in 'solid' enough ground? Each screw goes down as far as it needs to to reach that resistive torque?
@CornellEngineers 11 ай бұрын
Hi Mark Sometimes - but from my involvement with the guys designing screw piers their assessment of the torque requirement is tied to the soil testing carried out at design stage rather than blind trust that somewhere down there the screw pier will stop spinning. Torque then becomes the way the installer shows they have achieved the screw pier designer's requirements. Load testing can be carried out on installed screw piers in case there is uncertainty. Matt Cornell
@markharwood 11 ай бұрын
Understood. Thanks.
@dtran21k 11 ай бұрын
Do you recommend to use vapor barrier for footpath and concrete steps?😊
@CornellEngineers 11 ай бұрын
Hi @dtran21k Interesting question! I don't NOT recommend it. For the reason that the plastic prevents the ground sucking moisture out of the concrete I like it - but I recognise that a barrier isn't required under footpaths and external concrete steps to prevent rising damp. If the plastic is available and on site, then I'd suggest using it. If it is 'too hard' to get a roll of 0.2mm polyethylene membrane on your site then I'd question that answer but accept that it isn't really required. Matt Cornell
@brucef 11 ай бұрын
This deserves to be more popular, it assuages the (unneeded) worries that all owners of houses have when they see cracks.
@Matt.Cornell.Photography 11 ай бұрын
Thank you Bruce!!
@sarmonikasandy3934 11 ай бұрын
We just found a home we wish to buy and the rain 2022 eroded a large part of the hill the Queenslander is on. Great video
@kimuoi85 11 ай бұрын
Would it be expected for there to be exacerbated seasonal movements caused by the Feb 2022 Brisbane floods? About one year later we noticed a wider than usual crack in one corner of house - only 2mm wider
@CornellEngineers 11 ай бұрын
Hi Kim Flood waters and heavy rains do a couple of things to houses and each house is affected differently. A lot of water around a house can either soften the soil and turn it to mush (ie reduce the capacity of the soil to carry load), erode the soil (ie wash it away), cause the clayey soil to swell and lift (moreso in areas where the soil has always been dry) or any combination of these issues. Repairing a home straight after floods waters is problematic because the soil that has never been wet before is wet and has swelled. The soil that changes season to season is wet and has swollen too. Builders making repairs under these circumstances are locking unevenness into the house structure that has never been there before. As the always dry soil dries back out it shrinks and the ground surface drops. The wet soil around the outside continues to shrink and swell with the seasons. None of this will help you diagnose your 2mm wider crack - but it shows the complexities in the assessment with many factors unable to be accounted for (ie how deep the wet soil extended under the house where it can't be tested). So, an old house that used to move will eventually go back to moving just like it was. Occasionally the unevennes will be greater (or less) after a flood and occasionally th repair work will lock this unevenness in and result in cracks that had never existed before. At the end of the day - old houses on old foundation styles will continue to move season to season and also as the ground (that has never been wet before) dries out.. Rarely will the movement be so extreme that the house will be deemed unsafe. Allow your home to flex. Monitor it by all means. Understand that it is going to move again and again and modify your attitude and rectification methods to suit. Best of luck Matt Cornell
@shailvics Жыл бұрын
Very well explained..
@CornellEngineers Жыл бұрын
Thanks for watching!
@impactodelsurenterprise2440 Жыл бұрын
If you have two or three helixes that have progressive smaller pitches in relation to each other, would that compress the loose soil between the helixes as it goes down?
@CornellEngineers Жыл бұрын
Actually I have no idea if this would work. Let me defer to the gents that actually design and certify screw pier installations if any of them would like to comment!?!
@rogerjohansson3885 Жыл бұрын
Very good sir. Just a few things may need to be clarified. No mortar used. - When you dry stack (250 mm, best thickness, or) 200 mm ''the Besser'' -hollow concrete- blocks with 4-sides (two end-side) walls used with the method. The technology (you mention) design with open ends (illustrated) such as H-block, or even better with the "double H" type. Then to note concrete hollow blocks but with ends then shark jaws such as aligning next to each other. You can then simplify as a DIY builder and win big time gains and do it for the construction demonstration of basement- and/or any concrete residential DIY concrete solid walls without using molds. Check out my comment (with a lot of info) on the video "building the foundation" of (one who builds with solid and masonry Lecablocks, which is still associated with fire risk as not concrete then used when rebuilding a burned down previously built building again) Mind sparx (youtube). ''It's all in the wrist''? No, not really. It has (to make it simple) through the design for non-masons and non-carpenters to do with the design of the concrete blocks and how easy it is to be able to reinforce the blocks both vertically and horizontally. As well as being able to fill the blocks in all cavities with self-produced concrete. (You fill the wall in stages after building 3-4 stacked courses.) Using the wrong type of concrete block makes the work difficult DIY. The implication unnecessarily complicates the otherwise easiest way to build. Thus simply becomes more troublesome. In turn, which then discourages many DIY in e.g. In the US, using concrete and building concrete houses (which is really such a shame when there is just so much) easier than with the most common method in the US, 2''x4'' joist for walls.
@PanamaSticks Жыл бұрын
Sir: My family has had a 35 year battle with water seeping into the basement, soaking the block walls, causing efflorescense, soaking and cracking the basement and garage floors. My late parents got bad advice, and worse contractor work. No one in this area seems to know what they're doing except to trench the basement floor and run sump pumps. And then the problem is where to run the water, when there's nowhere to run it to. And what happens when the powee goes out? I am 69 years old and in poor health. I can no longer lug buckets of water up the stairs and throw them into the street. I hired an engineer last year, but he didn't have any good ideas, and wouldn't manage the project ir even write up a report. You seem to understand this stuff. I don't. Can I hire you, and can you find and wirk with a local contractor to get it solved? How do I contact your firm?
@CornellEngineers Жыл бұрын
A story we hear all too often. We might be able to help if the property is in Queensland. Head to our website and send us your details cornellengineers.com.au/contact-us/ If you're further afield it gets more difficult. Let's start with where you are and we can go from there. Matt Cornell
@lbrophy14 Жыл бұрын
Hi. Thanks so much for your video and webpage. This has been very enlightening. We are looking at possibly purchasing a home that was built 5 years ago in central Victoria. The owner built the home (we don’t know yet whether he is a registered builder or not but will find out). They have not hidden the fact that it has been built on a waffle slab. As a result during our research we have found your video. We are yet to view the property and before we go any further (eg getting engineers report etc) we are wondering whether after 5 years there are no signs of issues does this necessarily mean it’s ok. There are no carpets so it’s easy to inspect the slab. The block does not appear to be completely flat (from the photos). The property ticks a lot of boxes but your video has frightened us (good thing!). Can you assist us?
@CornellEngineers Жыл бұрын
Send me a message on my website with your phone number and I can call you for a chat. Matt
@understandingphysics1347 Жыл бұрын
I think this is due to improper curing. As the surface becomes dry crack appears.
@CornellEngineers Жыл бұрын
Perhaps, and yes even the underside of suspended concrete beams requires curing - but do you think that explains the even spacing of the cracks towrds the middle of the beam?
@MorThnMitDI Жыл бұрын
Thank you for sharing
@CornellEngineers Жыл бұрын
My pleasure!
@jesuscastellanos7038 Жыл бұрын
🤔good 👍
@CornellEngineers Жыл бұрын
I appreciate your comment. Thanks!
@sopwithpup01 Жыл бұрын
Hello and thanks for a fantastic video. I have a question regarding the building of a pad for the house. We are demolishing our house and am wondering whether, if the demolition crew were to leave a pad approximately 100-200 mm higher than the surrounding surface, if that would suffice? Or does it need to be specifically built up with clay? Thanks again
@CornellEngineers Жыл бұрын
What maters most is that you're already thinking about site drainage. It doesn't need to be specifically built up with clay - but old sand and gravel filled trenches that used to service the old house need to be considered and perhaps the easiest way to eliminate these 'old' sources of uneven ground moisture is just to dig them up and and do a whole new pad. Thanks for watching. Thanks even more for thinking about how to make your new build as good as possible. Glad I could be part of your journey! Matt Cornell
@sopwithpup01 Жыл бұрын
@@CornellEngineers Thanks very much for the reply Matt, really appreciate you taking the time to share your expertise. Cheers. Chris
@tremaynedejager8792 Жыл бұрын
Hi Matt, I am a design engineer from South Africa and found this video to be extremely helpful, thank you very much. I have been asked by a developer to look at using a waffle slab design on their houses. The majority of the site has been classified as a H2 site (15-30mm movement expected). We are also the civil engineers on the project so we can therefore make suggestions with regards to the height of the building pads. At the moment we have not specified any civil earthworks as the site has a nice gradual fall in one direction and we have therefore not deemed it necessary. What would your recommendation be regarding building platforms at civil construction phase and do you think that aprons around the house should be something that we should consider at all? Thank you in advance.
@CornellEngineers Жыл бұрын
Hi Tremayne Skip to this part in the video: kzbin.info/www/bejne/a3TYaYOOg5iKopY The problem mainly arises when the developer and then builder create dead flat building pads for houses. Yu have the advantage of a sloping site overall so use that to achieve falls in your trenches. Apron slabs in my opinion are not really worth the effort. They cover up poor drainage issues especially when the concrete apron slab is poured on sand (which is porous). Thanks for stopping by. I'm really pleased to have an engineer watching my videos! Matt Cornell
@tremaynedejager8792 Жыл бұрын
@@CornellEngineers Hi Matt, thanks a lot for coming back to me, I really appreciate it. Your view on apron slabs makes 100% sense to me, I will definitely keep that in mind in the future. I will definitely keep a close eye on civil construction and make sure that the sites slope away from the house as far as possible. With regards to patios and garages. What are your thoughts on designing patios and garages as separate waffle slabs to the house? My idea with this was to design them separately so that I can keep the bottom of all the slabs on the same level and so avoid the 'swimming pool' effect of water ponding in them due to them being lower than the surrounding area. Do you think that this is a good idea, or do you have any other suggestions?
@sdjnwhyNZ Жыл бұрын
If it's this serious for an inland scenario, it may be worse for a coastal house since everything in the air is salty.
@CornellEngineers Жыл бұрын
Possibly - but I think the issues are different. Corrosion and drainage are both significant issues that need to be addressed in new and old homes. Salt air and salt water are a problem for exposed steelwork - even for lightly galvanised steel. Whereas salt in the ground water won't be any worse as far as site drainage is concerned. Thanks for commenting and I hope yu enjoyed our videos! Matt Cornell
@Idealcorp Жыл бұрын
Love the video guys, thanks of the shout out!
@129GympieStreet Жыл бұрын
Idealcorp yours was a great video. Thanks for making it available to the good people of YT! Matt
@ricardolepe5575 Жыл бұрын
Hi Matt, i have an existing slab and we are renovating, moving the kitchen. we are relocating the sink drain pipe. so we are cutting the concrete slab 100mm wide approx 4000 mm long and its a waffle slab. do we need to fill in the waffle pods with concrete before filling the void with concrete? thank you for your time .